diff --git a/src/backend/threads.c b/src/backend/threads.c
index 4aeebbf23..2ec076978 100644
--- a/src/backend/threads.c
+++ b/src/backend/threads.c
@@ -92,25 +92,30 @@ thread_loop (void* thread)
       t->rh = &lumiera_lock_section_.rh;
 
       do {
+        lumiera_threadpool_release_thread(t);
+        LUMIERA_CONDITION_WAIT (t->state != LUMIERA_THREADSTATE_IDLE);
+        INFO (threads, "Thread awaken with state %d", t->state);
+
         // NULL function means: no work to do
         INFO (threads, "function %p", t->function);
         if (t->function)
           t->function (t->arguments);
-        lumiera_threadpool_release_thread(t);
-        LUMIERA_CONDITION_WAIT (t->state != LUMIERA_THREADSTATE_IDLE);
-        INFO (threads, "Thread awaken with state %d", t->state);
+        TRACE (threads, "function done");
+
+        if (t->kind & LUMIERA_THREAD_JOINABLE)
+          {
+            INFO (threads, "Thread zombified");
+            /* move error state to data the other thread will it pick up from there */
+            t->arguments = (void*)lumiera_error ();
+            t->state = LUMIERA_THREADSTATE_ZOMBIE;
+            LUMIERA_CONDITION_SIGNAL;
+            LUMIERA_CONDITION_WAIT (t->state == LUMIERA_THREADSTATE_JOINED);
+            INFO (threads, "Thread joined");
+        }
+
       } while (t->state != LUMIERA_THREADSTATE_SHUTDOWN);
       // SHUTDOWN state
 
-      if (t->kind & LUMIERA_THREAD_JOINABLE)
-        {
-          INFO (threads, "Thread zombified");
-          /* move error state to data the other thread will it pick up from there */
-          t->arguments = (void*)lumiera_error ();
-          t->state = LUMIERA_THREADSTATE_ZOMBIE;
-          LUMIERA_CONDITION_WAIT (t->state == LUMIERA_THREADSTATE_JOINED);
-          INFO (threads, "Thread joined");
-        }
 
       INFO (threads, "Thread Shutdown");
     }